Process of forming paper-board.



No. 645,374. Patented Mar. I3, 1900. K E noeens PROCESS OF FORMING PAPERBOARD.

(Application filed May 14, 1898.)

2 Sheets-Sheet l.

(No Model.)

m ML (5.

No. 645,374. Patented Mar. I3, I900.

K. E. ROGERS.

PROCESS OF FORMING PAPER BOARD.

(Application filed vMay 14, 189

2 Sheets--Shaat 2.

(No Model.)

Unwrap STATES PATENT KNIGHT E. ROGERS, OF MANCHESTER, CONNECTICUT.

hRocEss OF FORMING PAPER-BOARD.

$PEOIFIGATION forming part of Letters Patent N 0. 645,374, dated March13, 1900.

Application filed May 14, 1898- Serial No. 680,743. (No specimens.) 7

T0 aZZ whom, it may concern..-

Be it known that I, KNIGHT E. ROGERS, a citizen of the United States,residing at South Manchester, in the county of Hartford and State ofConnecticut, have invented certain new and useful Improvements inProcesses of Forming Paper-Board, of which the following is aspecification.

This invention relates to the art of making thick paper-board in acontinuous sheet, and it is particularly applicable for makingpressboard and the like, which when finished must have considerablestrength and stiffness and a smooth polished surface.

The object of the invention is to provide a simple process for cheaplymaking in a continuous sheet or web out of inexpensive stock withoutextensive beating and with the ordinary simple machinery now in use goodstrong thick paper-board which will finish very hard and smooth withoutwaste, which will not cockle or split when dried, and which may have itsopposite faces differently colored or of different qualities of stockwithout afiectingthehomogeneityoftheboard. Thick board of this naturecan be produced in sheets by winding on a press-roll a number of pliesof wet pulp from the felt of a cylinder-machine until the desiredthickness is reached and then cutting the pulp from the roll. These wetplies directly from the vat are of such constituency that they willadhere into a practically homogeneous mass when pressed. Such sheets arelimited in length, however, to the circumference of the roll upon whichthey are formed, and one surface will bear the marks of the felt.Besides the waste incident to the imperfectly-finished edges of shortsheets sheets require much handling and when dried in a loft buckle andcrinkle, so as to cause considerable loss in finishing,

. and sheets cannot have their opposite faces at best. Anattempt hasalso been made to form thick board in a web by forming a web of singleply, which after having been partially pressed and in a moist conditionis passed between press-rolls with a newly-formed web of pulp. With sucha process, however, the thickness of the material is limited, and oneply having been pressed more than the other the fibers are drier andmore compact. Therefore the adherence of the plies at most is onlypartial and the finished, stock easily splits apart. \Vith acylinder-machine by the employment of a number of cylinders with du=plicate felts and complicated machinery press-board of moderatethickness can be made if the best of stock is used, and a long time isconsumed in beating and mixing; but even with the best of stock and amost extensive reduction the thickness of the board is limited by theadherence of the material, for after a certain thickness is reached thepulp is liable to drop from the felt or become airmarked when passingthrough the rolls. The application of wet paste or glue to thin webs asthey come through a paper-machine is impracticable, particularly if theyare wet, for

the cementing material soaks into and permeates the pulpy material, andthus loses its adhering potency, and penetrating the pulp and squeezingout at the edges smears the rolls to such an extent that the quality andfinish of the surface of the paper are deleteriously affected. Thepresent invention resides in a process in which as one of the stepsthere is applied to couched to the felt of a Fourdrinier papermakingmachine of a cementing material in a dry-powdered form and then passingthis powdered layer between press-rolls with another layer consisting ofone or more plies of -wet pulp, and after repeating this until asufficient number of plies of wet pulp with dry powder between have beenbrought together, then subjecting these plies to the action of hotdrying-cylinders which steam,

IOO

cook, and harden the cementing compound in the interior in such mannerthat it does not strike through the body of the material, but unites theplies into a web of practically uniform homogeneity and of sufiicienthardness to permit its being subjected to the most vigorousglassing-machines for finishing and polishing the surfaces.

Of the accompanying drawings, Figure 1 represents a cylinderpaper-making machine with press-rolls, reel, and other mechanismsarranged for practicing the present invention; and Fig. 2 represents acontinuation of the mechanisms shown in Fig. 1 that may be employed incarrying out the invention.

This process can be carried out and thick board formed with a singlecylinder machine in the manner illustrated in Fig. 1. In that machinecommon paper-pulp stock beaten and mixed With only ordinary care iscirculated in the tank 1. This pulp is collected by the cylinder 2, fromwhich it is couched by the roll 3 onto the felt 4c, and after beingcarried between the first press rolls 5 is wound on a roll of the reel6. The reel shown is of the revolving type, and when one roll is filledthe web maybe cut and wound upon another. WVet webs 7 from two or morerolls of this reel are passed between press-rolls 8; but before passingthese second press-rolls the inner surfaces of the thin wet webs of pulpare given an even coating of dry cementing material that has been finelypulverized. This cementing material maybe flour, starch,- or anything ofa similar nature that when subjected to heat and moisture possesses therequisite adhesive properties and is capable of being finelypowdered.This powder may be sprinkled, dusted, or blown in suitable quantitiesevenly upon the surfaces of the webs. The powdered cementing material isplaced in receptacles 9, that are supported by standards 10, so as toextend transversely of the machine between the webs. These receptaclesare connected by pipes 11 with a fan .12, which is utilized to blow thepowderfrom the receptacles to the surfaces of the webs. The moisturesqueezed from the pulp as it passes through the second press-rollsdampens the powder and partially forms a paste, and the weight of therolls spreads this evenly, besides tending to unite the plies. The web13, thatis now formed of three plies, can be wound upon a roll ofanother reel lat. If it is desired to further increase the thickness ofthe paper-board, a number of webs 15 from this latter reel may be led tothird press-rolls 1 6. These webs before passing between the thirdpress-rolls have their surfaces dusted with powdered dry pastethat maybe blown from receptacles 17, supported and arranged with a fan 18, asare the receptacles 9. The pressure of these rolls assists in thetransformation of the powder on the inner'surfaces of the wet webs intopaste. The web 19, that issues from the third press-rolls, will containnine plies of wet pulp, and if this is of sufficient thickness it may beled to the cylinders of a drying-machine 20. In passing around andbetween the heated cylinders of .the drying-machine steam is generatedfrom the moisture in the plies and this cooks the partially-formedpaste, and as the web traverses the rolls this paste is graduallyhardened as the board is dried and solidified until when the boardemerges from the drier the paste has been treated and solidified in suchmanner between the plies that the finished web of board has practicallythe homogeneity of a single ply.

The paper-board formed by this process is when dried usually moistenedand then subjected to the action of calendering-rolls or the vigorouspolishing of a glassing-jack for giving the finishing polish to thesurface.

By means of this process paper-board of any desired thickness may beformed into a continuous web of such homogeneity that it will not splitor come apart when moistened for finishing, or when under theglassing-jack or other calender-rolls, or if it is moistened in dyeingliquor. Any ordinary single cylinder Fourdrinier or combination machinemay be fitted for practicing this process, and it does not require theuse of expensive stock nor is it necessary that a long and extendedbeating be given to the stock in order to insure a thorough adhesionbetween the plies of the pulp.

With this process the cementing material for the plies does not strikeinto the body of the pulp, but remains on the surface of the layersuntil thoroughly moistened, steamed, and set by the heated drying-rolls.By dusting the dry powder on the wet webs of pulp a very evendistribution of just the sufficient quantity of material may be obtainedto insure perfect adhesion without affecting the quality or color of theboard. Vith the webs run together as described the surfaces with thefelt-marks will be in the interior, so that the finished board will notbedisfigured. If it is desired, one web may be made of one color andanother web a diiferent color, and these may be colored before being runtogether, so that the finished board will have its opposite sidescolored differently. One ply may be made of cheaper material than theother or an inside ply may be cheaper than the two outside plies or of adifierent color from the outside plies, and still the resulting boardwill be very dense and have between continuously-moving undried webs,and dry and harden the board, substantially pressing together the websthus dusted with as specified.

dry powder and subjecting the compound web thus powdered and united toheat and KNIGHT ROGERS pressure to form the moisture of the pulpWitnesses:

and the powder between the webs into a H. R. WILLIAMS,

strongly-adhering paste and solidifythe paste E. W. FOTHERGILL

